After WW2 the Labour government invested heavily into a better country with the creation of the welfare state and building council houses. It made the economy stronger not weaker! So stop blaming immigration and educate yourself.
No it didn't. After the war the USA introduced a scheme known as Marshall Aid, which was loans and grants to war devastated European countries, including Britain, to rebuild their industries and revive their economies, which is what countries like Germany, France, Italy etc did.
In this country the Labour government chose to use thaat money to fund the start up of the NHS. To them it seemed the best investment at the time, but the result was that in the 1950s and 60s, British industry started its slide into oblivion and our productivity compared with other countries got poorer and poorer - and still remains so.
This was because other European countries used the Marshall Aid to build new factories with modern equipment, which meant reduced costs of production and high productivity while out manufacturers were lumbered with old outdated factories and equipment and labour practices that belonged in the 19th century.
Much of the new public sector housing, especially in cities was badly built, had problems from new and are now forming our current slums until such time as they can be demolished.
Labour can be proud of the NHS, but it was the Conservatives that brought in the Education Act. I do agree that we should not blame immigration for anything, since the amjority of immigrants are here quite legally as the result of government(all parties) manpower planning decisions to buy in skilled people from abroad rather than invest in training our own skilled people.